#include <stdio.h>
#define START 3500
int main()
{
    double income, tax;
    scanf("%lf", &income);
    income = income - START;
    if (income <= 0)
    {
        tax = 0;
    }
    else if (income <= 1500)
    {
        tax = income * 0.03;
    }
    else if (income <= 4500)
    {
        tax = income * 0.1 - 105;
    }
    else if (income <= 9000)
    {
        tax = income * 0.2 - 555;
    }
    else if (income <= 35000)
    {
        tax = income * 0.25 - 1005;
    }
    else if (income <= 55000)
    {
        tax = income * 0.3 - 2755;
    }
    else if (income <= 80000)
    {
        tax = income * 0.35 - 5505;
    }
    else 
    {
        tax = income * 0.45 - 13505;
    }

    if (tax > 0)
    {
        printf("%.2f元", tax);
    }
    else
    {
        printf("不用交税");
    }
    

    return 0;
}